Six months I ago I doubt even Josesito Lopez would have imagined that on the biggest boxing weekend of the year—Mexican Independence Day—he would be headlining a premium cable card against one of the sport's hottest young stars.

But when Lopez (30-4, 18 KOs) broke Victor Ortiz's jaw last June 23, he earned the opportunity to challenge Saul Alvarez (40-0-1, 29 KOs) for his WBC junior middleweight belt, bumping Ortiz from the spot he had already been announced for.

They will meet tonight, at the MGM Grand in Las Vegas, Nevada. The fight will be broadcast live on Showtime.

Lopez will be a heavy underdog in the betting, but nobody doubts that he will show up tonight looking to make a fight of it. He is a pressure fighter with a solid chin and respectable power. Expect him to stay within range of Alvarez, looking to exchange up close.

But he will be facing a bigger man. His TKO of Ortiz was his first major fight at welterweight, after spending almost his entire career at 140.

Now he will step up in weight once again, to challenge Alvarez at 154.

A major star in Mexico since his teenage years, the 22-year-old Alvarez is viewed by many as a boxing prodigy, a young champion at the start of a legendary career.

Both men are aggressive, yet intelligent, brawler-boxers. I have to give Alvarez the advantages in strength, explosiveness and overall athleticism, but Lopez has a gritty, intangible aspect that keeps him in fights and in position to win.

I will be blogging with round-by-round scoring in the main event and highlights from the under card, starting at 9 p.m.